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authorMike Looijmans <mike.looijmans@topic.nl>2018-03-29 07:29:48 +0200
committerDavid S. Miller <davem@davemloft.net>2018-03-30 10:40:18 -0400
commit9217e566bdee4583d0a9ea4879c8f5e004886eac (patch)
tree7bb19099d401d2e50b46112173f35435268eb6e9 /drivers/of
parent64e828dfc4853a396d2c0b25c22a4c5066aab76a (diff)
of_net: Implement of_get_nvmem_mac_address helper
It's common practice to store MAC addresses for network interfaces into nvmem devices. However the code to actually do this in the kernel lacks, so this patch adds of_get_nvmem_mac_address() for drivers to obtain the address from an nvmem cell provider. This is particulary useful on devices where the ethernet interface cannot be configured by the bootloader, for example because it's in an FPGA. Signed-off-by: Mike Looijmans <mike.looijmans@topic.nl> Reviewed-by: Florian Fainelli <f.fainelli@gmail.com> Reviewed-by: Andrew Lunn <andrew@lunn.ch> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'drivers/of')
-rw-r--r--drivers/of/of_net.c40
1 files changed, 40 insertions, 0 deletions
diff --git a/drivers/of/of_net.c b/drivers/of/of_net.c
index d820f3edd431..53189d4022a6 100644
--- a/drivers/of/of_net.c
+++ b/drivers/of/of_net.c
@@ -7,6 +7,7 @@
*/
#include <linux/etherdevice.h>
#include <linux/kernel.h>
+#include <linux/nvmem-consumer.h>
#include <linux/of_net.h>
#include <linux/phy.h>
#include <linux/export.h>
@@ -80,3 +81,42 @@ const void *of_get_mac_address(struct device_node *np)
return of_get_mac_addr(np, "address");
}
EXPORT_SYMBOL(of_get_mac_address);
+
+/**
+ * Obtain the MAC address from an nvmem provider named 'mac-address' through
+ * device tree.
+ * On success, copies the new address into memory pointed to by addr and
+ * returns 0. Returns a negative error code otherwise.
+ * @np: Device tree node containing the nvmem-cells phandle
+ * @addr: Pointer to receive the MAC address using ether_addr_copy()
+ */
+int of_get_nvmem_mac_address(struct device_node *np, void *addr)
+{
+ struct nvmem_cell *cell;
+ const void *mac;
+ size_t len;
+ int ret;
+
+ cell = of_nvmem_cell_get(np, "mac-address");
+ if (IS_ERR(cell))
+ return PTR_ERR(cell);
+
+ mac = nvmem_cell_read(cell, &len);
+
+ nvmem_cell_put(cell);
+
+ if (IS_ERR(mac))
+ return PTR_ERR(mac);
+
+ if (len < ETH_ALEN || !is_valid_ether_addr(mac)) {
+ ret = -EINVAL;
+ } else {
+ ether_addr_copy(addr, mac);
+ ret = 0;
+ }
+
+ kfree(mac);
+
+ return ret;
+}
+EXPORT_SYMBOL(of_get_nvmem_mac_address);